1. Field of the Invention
The present invention relates to a battery pack, information processing apparatus, charge control system, charge control method by battery pack, and charge control method by charge control system. More particularly, the present invention relates to a technique for controlling the amount of current or an output stop function at a charger depending on a temperature of the battery pack.
2. Description of the Related Art
In related art, battery charging has been generally performed by a current having a certain current value irrespective of an environmental temperature. In this case, the charge reaction is a chemical reaction and is largely influenced by a temperature. When charging is performed by a current having a certain current value, a likelihood of side-effect or a state of charge product is largely different depending on the temperature. Thus, many manuals or recommended standards for safe usage of a battery pack and the like for a personal computer have been issued from various institutions and battery charge control requires to be reconsidered (see Non-Patent Document 1, for example).
A charge current value is desirably reduced in low and high temperature ranges having a security risk while more charge current and reduced charge time are required in terms of usability. The conflicting charge specifications require to be met.    [Non-Patent Document 1] “Manual for safe usage of lithium ion secondary battery in notebook type PC”, [online], 20 Apr. 2007, Japan Electronics and Information Technology Industries Association, Battery Association of Japan, [16 Jun. 2008 searched], Internet <http://it.jeita.or.jp/perinfo/committee/pc/battery/070420.pdf>